5,2

Table of n, a(n) for n=5..29.

Wikipedia, Coprime integers

Wikipedia, Partition of a set

Column k=5 of A280880.

Sequence in context: A074891 A328213 A271733 * A306325 A241282 A249056

Adjacent sequences: A280880 A280881 A280882 * A280884 A280885 A280886

nonn

Alois P. Heinz, Jan 09 2017

approved